White noise is not the same as other sounds. Even a quiet environment does not have the same effect as this noise. Against the background of sustained noise, hearing pure tones becomes even more precise, researchers have shown. Their findings could therefore be transferred to the further development of cochlear implants. Despite the importance of hearing in human communication, we still understand very little about how we perceive and process acoustic signals. However, one thing is clear: the more accurately we can distinguish sound patterns, the better our hearing is. But how does the brain manage to distinguish between relevant and less relevant information - especially in an environment with background noise?
White Noise – Exploring the Auditory Brain
Researchers led by Prof. Dr. Tania Rinaldi Barkat from the Department of Biomedicine at the University of Basel investigated the neural basis of sound perception and sound discrimination in a challenging sound environment. The focus was on researching the auditory cortex. This is an area of the brain where we process acoustic stimuli. However, the resulting patterns of activity come from measurements in the brain of a laboratory mouse.
As is well known, distinguishing between sounds becomes more difficult the closer they are in the frequency spectrum. The researchers initially assumed that additional noise could make such a listening task even more difficult. However, the opposite was observed: the team showed that the brain's ability to detect subtle differences in tone improved when white noise was added to the background. Compared to a quiet environment, the noise made hearing perception easier.
Noise reduces neuronal activity
The working group's data showed that white noise significantly inhibits the activity of nerve cells in the auditory cortex. Paradoxically, this suppression of neuronal excitation led to a more accurate perception of pure tones. “We found that with two different sound representations, there is less overlap between neuronal populations,” explains Professor Tania Barkat. “As a result, the overall reduction in neural activity resulted in a clearer sound representation.”
To confirm that the auditory cortex, and not another area of the brain, is responsible for changing sound perception, the researchers used the light-controlled technique Optogenetic. We could potentially use their findings to improve auditory perception in situations where sounds are difficult to distinguish. According to Barkat, it is conceivable that medicine can stimulate the ear with a similar effect to white noise in order to improve the frequency resolution and thus the hearing results of its users.
You can find out more about ithereread.
